Abstract
The preparation of graphites has been worked by pyrolysis of propane gas on a directly heated substrate in the vapor phase stirred by a fan. Its formation process and structural features (microstructure, density, and crystal structure) were examined on several samples deposited under various conditions at deposition temperatures of 1440, 1730, 2025°C, gas pressures of 10, 25, 50mmHg, and gas flow rate of 640cm3/min. The effect of stirring vapor phase is appreciable at high temperatures and high pressures. The convection of the decomposed gases or gaseous products disappears in the stirred vapor phase. It follows that the abnormal behavior observed in the pressure range of 20∼30mmHg as described in a previous paper is restored to its normal behavior. The formation process in the stirred vapor phase is discussed in relation to the change in the structural features under the gas pressure.
